I think it also depends on your tolerance to certain oils. I get more pip from mct vs Gso it seems.PIP usually comes down to your body not able to handle a higher concentration. The easy solution is to just dilute it. Had some PIP with his T500 (which honestly a bit of PIP is to be expected at that concentration), after going 50/50 with castor oil it fixed the problem. And oral castor oil is apparently good for hair growth, so maybe injecting it as a carrier oil is even better.